What
On each turn Claude Code attaches a short note about the environment, including the primary working directory (the folder the session works in). It now notices when that folder stops existing or starts existing again. When it does, it tells the model "The primary working directory announced earlier no longer applies." and logs the change.
The environment summary rebuilt after compaction (when a long conversation is shortened to save space) now comes from the same logic. The check is skipped for bare forks of the conversation and for isolated contexts.
Why
The model stops acting as though it can still work in a folder that has been deleted out from under it.
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubt
One further condition decides whether the check runs, and what it is was not resolved.